| 摘要 |
<p>An upper face plate, a lower face plate, and a cylindrical flexible film body with opposite ends respectively connected air-tightly to the upper face plate and the lower face plate are provided. A pressurized gas of a pressure equal to or greater than atmospheric pressure is sealed within. A sliding plate of polyethylene resin with a weight average molecular weight of two million or more is provided on at least one of mutually opposing faces of the upper face plate and the lower face plate.</p> |
